The present invention relates generally to a stack pack construction of an electrolytic cell for the generation of chlorates or hypochlorites of sodium or potassium utilizing repeatable components which are mass produced to build electrolytic cells having various capacities in addition to having either monopolar or bipolar configurations for efficient use of existing electrical supply equipment. More particularly, the present invention relates to an improved stack pack type electrolytic cell for the production of sodium hypochlorite having repeatable enclosure and electrode stack pack components which can be mass produced in the most efficient manner to build electrolytic cells of varying capacities and varying electrode configurations. This employs the use of two end plates with structural cross members which can be utilized with tie rods between two such end plates to compress the chambers and stack packs therebetween. The various chambers which are utilized between these two end plates can be mass produced by injection molding or other plastic molding operations to provide a very uniform workpiece for the assembly of various sized electrolytic cells.
Active chlorine in the form of sodium hypochlorite has been used for some time as a biocidally active agent for treatment of sewage, liquid effluents, water in swimming pools, cooling tower waters, or drinking water. Generally, such treatment is affected by the use of rather large volumes of chemical compounds each as sodium hypochlorite or molecular chlorine, if available. The addition of such chemical compounds to affect the biocidal activity desired has become costly and is likely that greater restrictions upon the traffic of dangerous chemical products in the transportation networks of the world will necessitate on-site manufacture of such compounds or a different means by which treatment may be carried out. For some time now, it has been known that electrochemical methods of manufacture present one solution to this problem due to their capability for small on-site production at a reasonable cost, greater ecological acceptability, and potential for energy conservation. Furthermore, electrochemical methods of manufacture can generally be operated as closed systems thereby allowing greater control over the escape of biproducts or waste products from the electrolytic cells which may have been environmentally undesirable. Electrolytic cells promise to be one of the most efficient means of utilizing electricity which is likely to be used more in the future due to the rapidly rising costs and expected exhaustion of fossil fuels such as coal, gas, and oil.
Where there are readily available supplies of saltwater (brine) such as seawater, aqueous solutions of hypochlorite solution can be readily made by electrolysis of seawater. The problem has been that with specified capacities of such seawater electrolytic cells, storage of product compound is often necessitated by the uneven usage of drinking water or uneven production of sewage for treatment. Thus, one of the problems of use of electrolytic cell is the sizing of such a cell to the given capacity needs of each individual treatment plant in order to best conserve the need for massive storage facilities which cause numerous problems. Very often in the past, an electrolytic cell having a small capacity was designed and build such that several such units could be ganged together to provide the given capacity necessary for any given operation. This, however, involves inefficiencies of the use of materials such as electrode components in chambers and additional piping necessary for such cells to the extent where costs can rapidly exceed economical commercial realization of the full potential of such an electrolytic chlorine generation system because of the number of units associated equipment therewith, especially for large volume operations.
Therefore, it would be exceedingly advantageous to develop an electrolytic cell system for the generation of hypochlorite utilizing a brine solution that can be adequately sized for various production capacities and, in accordance with existing electrical supply equipment to thereby reduce substantially the cost for the use of such cells in the production of water treatment compounds.